# std::rend, std::crend

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< cpp‎ | iterator

Defined in header `<array>` |  |
Defined in header `<deque>` |  |
Defined in header `<flat_map>` |  |
Defined in header `<flat_set>` |  |
Defined in header `<forward_list>` |  |
Defined in header `<inplace_vector>` |  |
Defined in header `<iterator>` |  |
Defined in header `<list>` |  |
Defined in header `<map>` |  |
Defined in header `<regex>` |  |
Defined in header `<set>` |  |
Defined in header `<span>` |  |
Defined in header `<string>` |  |
Defined in header `<string_view>` |  |
Defined in header `<unordered_map>` |  |
Defined in header `<unordered_set>` |  |
Defined in header `<vector>` |  |
template< class C > auto rend( C& c ) -> decltype(c.rend()); | (1) | (since C++14) (constexpr since C++17)
template< class C > auto rend( const C& c ) -> decltype(c.rend()); | (2) | (since C++14) (constexpr since C++17)
template< class T, std::size_t N > std::reverse_iterator<T*> rend( T (&array)[N] ); | (3) | (since C++14) (constexpr since C++17)
template< class T > std::reverse_iterator<const T*> rend( std::initializer_list<T> il ); | (4) | (since C++14) (constexpr since C++17)
template< class C > auto crend( const C& c ) -> decltype(std::rend(c)); | (5) | (since C++14) (constexpr since C++17)

Returns an iterator to the reverse-end of the given range.

1,2) Returns c.rend(), which is typically an iterator one past the reverse-end of the sequence represented by c.
1) If `C` is a standard Container, returns a `C::reverse_iterator` object.
2) If `C` is a standard Container, returns a `C::const_reverse_iterator` object.
3) Returns an std::reverse_iterator<T*> object to the reverse-end of array.
4) Returns an std::reverse_iterator<const T*> object to the reverse-end of il.
5) Returns std::end(c), with c always treated as const-qualified.
If `C` is a standard Container, returns a `C::const_reverse_iterator` object.

### Parameters

c | - | a container or view with a `rend` member function
array | - | an array of arbitrary type
il | - | an std::initializer_list

### Return value

1,2) c.rend()
3) std::reverse_iterator<T*>(array)
4) std::reverse_iterator<const T*>(il.begin())
5) c.rend()

### Exceptions

May throw implementation-defined exceptions.

### Overloads

Custom overloads of `rend` may be provided for classes and enumerations that do not expose a suitable `rend()` member function, yet can be iterated.

Overloads of `rend` found by argument-dependent lookup can be used to customize the behavior of std::ranges::rend and std::ranges::crend. | (since C++20)

### Notes

The overload for std::initializer_list is necessary because it does not have a member function `rend`.

### Example

Run this code

    #include <algorithm>
    #include <iostream>
    #include <iterator>
    #include <vector>

    int main()
    {
        int a[]{4, 6, -3, 9, 10};
        std::cout << "C-style array `a` backwards: ";
        std::copy(std::rbegin(a), std::rend(a), std::ostream_iterator<int>(std::cout, " "));

        auto il = {3, 1, 4};
        std::cout << "\nstd::initializer_list `il` backwards: ";
        std::copy(std::rbegin(il), std::rend(il), std::ostream_iterator<int>(std::cout, " "));

        std::vector<int> v{4, 6, -3, 9, 10};
        std::cout << "\nstd::vector `v` backwards: ";
        std::copy(std::rbegin(v), std::rend(v), std::ostream_iterator<int>(std::cout, " "));
        std::cout << '\n';
    }

Output:

    C-style array `a` backwards: 10 9 -3 6 4
    std::initializer_list `il` backwards: 4 1 3
    std::vector `v` backwards: 10 9 -3 6 4

### See also

endcend (C++11)(C++14) | returns an iterator to the end of a container or array (function template)
rbegincrbegin (C++14) | returns a reverse iterator to the beginning of a container or array (function template)
begincbegin (C++11)(C++14) | returns an iterator to the beginning of a container or array (function template)
ranges::rend (C++20) | returns a reverse end iterator to a range (customization point object)
ranges::crend (C++20) | returns a reverse end iterator to a read-only range (customization point object)

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